What is electroplating? Explain the process. Give two uses of electroplating.
Electroplating is a process that uses electric
current to reduce dissolved metal cations so that they form a thin coherent
metal coating on an electrode. The term is also used for electrical oxidation
of anions onto a solid substrate, as in the formation silver chloride on silver
wire to make silver/silver-chloride electrodes. Electroplating is primarily
used to change the surface properties of an object (e.g. abrasion and wear
resistance, corrosion protection, lubricity, aesthetic qualities, etc.), but
may also be used to build up thickness on undersized parts or to form objects
by electroforming.
Electroplating is known as electrodeposition
because the process involves depositing a thin layer of metal onto the surface
of a work piece, which is referred to as the substrate. An electric current is
used to cause the desired reaction.
Here’s a simplified explanation of how
electroplating works: Let’s suppose that a layer of gold is to be
electrodeposited onto metal jewelry to improve the appearance of the piece. The
plating metal (gold) is connected to the anode (positively charged electrode)
of the electrical circuit, while the jewelry piece is placed at the cathode
(negatively charged electrode). Both are immersed in a specially developed
electrolytic solution (bath).
At this point, a DC current is supplied to the
anode, which oxidizes the metal atoms in the gold and dissolves them into the
bath. The dissolved gold ions are reduced at the cathode and deposited (plated)
onto the jewelry piece. Factors that impact the final plating result include:
a) the chemical composition and temperature of the
bath
b) the voltage level of the electric current
c) the distance between the anode and the cathode
d) the electrical current application’s length of time.
Uses: Common uses of electroplating include:
a) Building the thickness of a metal surface
b) Increasing wear resistance
Electroplating is a process that uses electric current to reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode. The term is also used for electrical oxidation of anions onto a solid substrate, as in the formation silver chloride on silver wire to make silver/silver-chloride electrodes. Electroplating is primarily used to change the surface properties of an object (e.g. abrasion and wear resistance, corrosion protection, lubricity, aesthetic qualities, etc.), but may also be used to build up thickness on undersized parts or to form objects by electroforming.
Electroplating is known as electrodeposition because the process involves depositing a thin layer of metal onto the surface of a work piece, which is referred to as the substrate. An electric current is used to cause the desired reaction.
Here’s a simplified explanation of how electroplating works: Let’s suppose that a layer of gold is to be electrodeposited onto metal jewelry to improve the appearance of the piece. The plating metal (gold) is connected to the anode (positively charged electrode) of the electrical circuit, while the jewelry piece is placed at the cathode (negatively charged electrode). Both are immersed in a specially developed electrolytic solution (bath).
At this point, a DC current is supplied to the anode, which oxidizes the metal atoms in the gold and dissolves them into the bath. The dissolved gold ions are reduced at the cathode and deposited (plated) onto the jewelry piece. Factors that impact the final plating result include:
a) the chemical composition and temperature of the bath
b) the voltage level of the electric current
c) the distance between the anode and the cathode
d) the electrical current application’s length of time.
Uses: Common uses of electroplating include:
a) Building the thickness of a metal surface
b) Increasing wear resistance
